David Salisbury, Department of Health"We're not convinced by this claim" real 28k

Monday, 10 April, 2000, 10:23 GMT 11:23 UK

Fresh MMR autism link rejected

Links between MMR and autism are not proven

Experts say the latest study to link the measles virus and autism is deeply flawed.

The research, which claims to have found traces of the virus in the guts of children with autism, comes from Dr Andy Wakefield, whose research sparked the first MMR scares two years ago.

But the Royal Free and University College Medical School in London, where Dr Wakefield is based, has issued a statement pointing out weaknesses in the research.

And Department of Health officials, concerned that any reduction in vaccination rates leaves children vulnerable to disabling or even fatal infection, insist that the MMR jab is safe.

The latest research was presented to the US Congress last week by Dr Wakefield and Professor John O'Leary, director of pathology at Coombe Women's Hospital in Dublin.

He said that in 25 children with autism, 24 had traces of the measles virus in their gut.

Professor O'Leary said there was now "compelling evidence" of a link between autism and MMR.

This association, however, would not in itself confirm that the virus causes autism, or even that the source of the virus found is the MMR vaccination, which contains "dead" versions of the measles and mumps viruses.

'Unverifiable'

The Department of Health said the research was "unverifiable by usual scientific means".

"It does not prove anything and there remains no evidence to suggest there is any link between the MMR jab and autism," a spokesman added.

"It would be a disaster if children were to die of vaccine-preventable diseases over unfounded vaccine safety scares."

And a spokesman for the Royal Free Hospital said that no other scientists had yet been able to reproduce or verify Dr Wakefield's work.

She pointed out that another study suggested that the chemical tests carried out by Dr Wakefield to confirm the presence of measles virus could have been rendered positive by a normal gut protein.

"Dr Wakefield has been strongly urged to
undertake a further study which would include blind testing of subjects, appropriate controls and independent testing by the disinterested expert laboratories."

Dr Wakefield's original small-scale research suggested that many children developed autism shortly after receiving the MMR jab, but a much larger Medical Research Council (MRC) study published last year found no evidence of a link.

The MRC has commissioned a much larger research project to try to determine the causes of autism.

While children infected with the natural measles virus can die in a very small number of cases, it can also lead to serious complications, particularly in the very young.

These can include pneumonia, bronchitis, convulsions and even meningitis.

The rate of uptake for the MMR vaccination fell sharply after the publication of Dr Wakefield's first research, which linked MMR with both autism and Crohn's disease.